Car loses power with initial acceleration

I have a 2003 Kia Optima, (4cyl?) automatic, 4 door. I just had the oil changed. When I accelerate past 20-30 mph, the car will "hiccup" I will lose power, I will hear a click, the engine light will turn on. When I floor the gas, everything will go to normal. After a mile or so, no problems. The engine light does not stay on.